Drawing machine

ABSTRACT

A drawing machine is disclosed, adapted for association with drawing boards of considerable dimensions. The machine is characterized in that it comprises at least two guiding columns mounted on a base structure, the columns receiving therein reciprocable rods having lateral tubular members secured to the ends thereof, projecting from the respective columns. These lateral tubular members are connected by slidable sleeves providing for limited rotation of said rods in respect of each other in two planes. Conical couplings carrying thereon bracket means for supporting the drawing board are mounted on the respective free ends of the lateral tubular members and are interconnected by an elongated resilient connecting member passing through the lateral tubular members and holding them together in the direction of the longitudinal axis thereof.

United States Patent Perminov [451 Aug. 8, 1972 DRAWING MACHINE Primdry-Examiner-Harry N. Haroian 72 Inventor: Evgeny Mikhailovich Pei-1mm, ulitsa Angarskaya, 26, Korpus l, Kv. l0, Minsk, USSR. 1

ABSTRACT 22 H d: A drauzing machine is disclosed, adapted forassocia- 1 Dec 1970 tion w1th drawing boards of considerable dimensions. [21] Appl. No.: 102,673 The machine is characterized in that it comprises at least two guiding columns mounted on a base structure, the columns receiving therein reciprocable rods [30] Fm'gn Application Priomy having lateral tubular members secured to the ends Feb. 24, 1970 U.S.S.R. 1400962 thereof, p j g from the respective columns- These lateral tubular members are connected by slida- :.::.il "108/61; ble Sleeves providing for limited rotation of said rods t f h 58 Field of Search ..l08/6, 7, 10, 144; 312/231; "i m planes 33/76 Conical coupllngs carrymg thereon bracket means for supporting the drawing board are mounted on the [56] References Cited respectiye free ends of the lateral tubular members and are interconnected by an elongated reslllent con- UNITED STATES PATENTS necting member passing through the lateral tubular members and holding them together in the direction 3,358,620 12/1967 Par1g1 ..'.l08/6 3,543,282 11/1970 Sautereau ....l-08/6 "Q am there 8 Claim, 9 Drawing Figures l5 I3 22 I4 2/ 73 47 24 A II I PATENTEDA 1912 SHEET 2 [1F 4 h wt PATENTEDAUG 8I972 l 3.682.108

sum 3 or 4 PATENTEOAUB M2 3.682.108

SHEET [)F 4 FIG. 5

kflllllllll"! DRAWING MACHINE The present invention relates to arrangements designed for mechanization of drawing and graphic works, and, more particularly, it relates to drawing machines.

A drawing machine, constructed in accordance with the present invention, can be successfully used in association with a drawing mechanism of the coordinate type.

A drawing machine is known, comprising a guiding column belonging to the base structure, this colunm receiving thereinside a reciprocable rod provided with rollers engaged in rolling contact with the internal wall of said column, this rod having a lateral tubular member attached to the end thereof, projecting from said column.

The opposite ends of this lateral tubular member carry conical couplings provided with brackets for supporting thereon the drawing board. The two couplings are interconnected by means of a resilient connecting member, this member being operatively connected through an elongated cable with a drum assembly mounted in the base structure, this drum assembly being adapted to counterbalance the rod, with the help of torsion springs mounted inside this drum. One end of each such torsion spring is connected with the drum, while the opposite end of the torsion spring is connected with the shaft supporting this drum, this shaft being operatively connected by means of an arm mounted on the end portion of this shaft with a control pedal mounted on the base structure.

Located adjacent to the external periphery of this drum is a flat elastic band making at least one loop about the drum, the band having the opposite ends thereof connected to the base structure and being adapted to efiect retaining of the abovementioned rod at a desired height of its projection from the column.

The abovedescribed known drawing machine is both convenient in operation and inexpensive in manufacture.

However, this known drawing machine can support drawing boards within a limited range of their lengths. Should the drawing board be of an excessive length, i.e., of a length above this limited range, the telescopic couple of the machine (the rod column couple) is subjected to excessive loads and starts displaying inadequate rigidity, whereas the machine, as a whole, becomes relatively unstable.

It is an object of the present invention to eliminate this disadvantage.

The main object of the present invention is to provide a drawing machine which should be capable of association with drawing boards of practically and size (particularly, of any length), and that, with employing all the major assemblies and component parts of a single basic model of such drawing machine.

This object is accomplished, in accordance with the present invention, in an improved drawing machine of the above-described type, wherein, for association with a drawing board of a considerable size, the said machine comprises at least two guiding columns receiving thereinside a pair of respective reciprocable rods carrying the respective lateral tubular members connected with each other by means of slidable sleeve means, whereby the rods are free for limited rotation relative to one another in at least two planes, the coupling means being mounted on the free ends of said lateral tubular members and interconnected by a resilient connecting member, said last-mentioned member passing through all said lateral tubular members carried by all said reciprocable rods, and thereby holding these tubular members together in the direction of the longitudinal axes thereof.

With the rods being operatively connected in the above-described way, they can be easily reciprocated in their respective guiding columns, because each individual one of said rods is able to align itself in respect of its guiding column.

It is expedient for the ends of each one of said lateral tubular members to have made therein cylindrical counterbores for receiving therein either the slidable sleeves with their washers, or else the coupling members of the conical couplings, each said coupling member being an externally cylindrical part with a conical internal bore.

With the lateral tubular members being so constructed, their assembling is facilitated, and they become fully interchangeable.

It is further expedient for said externally cylindrical parts to be made of an elastic plastic material.

In this way the manufacture of such parts becomes more simple, and the performance of the friction couples of the couplings is improved.

Practicaltests have proved that the most convenient way of connecting the conical couplings with the resilient connecting member is to use threaded connections for the purpose.

The threaded connections make it possible to adjust the tension of the resilient connecting member in the course of the assembling of the drawing machine.

Practical tests have also shown that it is further expedient for the rollers carried by each said reciprocable rod to be arranged so that two pairs of rollers should be mounted thereon for rotation about their respective axes rigidly secured to the rod at diagonal points along the length thereof, at one pair of the opposite sides of this rod, and that two more roller should be mounted, respectively, on a pair of spring-biased pivotable arms having the respective pivot axes thereof positioned on said rod at diagonal points along the length of said rod, at the other pair of the opposite sides thereof.

With the rollers so arranged on each said rod,

jamming of the rod in its guiding column is positively prevented, and there are created the conditions for practically complete elimination of play in the telescopic couple (the column rod couple).

It is also expedient for a drawing machine, con- I columns, it is expedient for these columns to be mounted on three individual bases and to have the flat elastic band, adapted to control the positioning of the rods at a desired height, associated only with that one of the drums, which is located beneath the central one of the three rods.

With a drawingmachine so arranged, it can be used for mounting thereon a drawing board of practically any length, the individual bases being spaced from each other by any appropriate distance.

When the reciprocable rods are thus considerably spaced from each other, it is expedient for the slidable sleeves interconnecting the adjacent pairs of the lateral tubular members to have mounted thereon additional brackets for providing additional support for the drawing board.

Other objects and advantages of the present invention will become apparent from the following detailed description of an embodiment thereof, with reference being had to the accompanying set of drawings, wherein:

FIG. 1 is a partly broken away general side view of a drawing machine, embodying the invention;

FIG. 2 is an enlarged sectional view taken along line 11-11 of FIG. 1;

FIG. 3-is an enlarged sectional view taken along line IIIIII F FIG. 1;

FIG. 4 is an enlarged sectional view taken along line IV-IV of FIG. 1;

FIG. is an enlarged view of the portion A of FIG. 4;

FIG. 6 is an enlarged view taken along the arrow line 8" ofFIG. 1;

FIG. 7 is an enlarged sectional view taken along line VII-VII of FIG. 6;

FIG. 8 shows a modification of a drawing machine constructed in accordance with the present invention, having three guiding columns supported by their individual bases;

FIG. 9 shows an additional bracket for supporting the drawing board, mounted on the slidable sleeve.

Referring now in particular to the appended drawings, a drawing machine embodying the invention includes a ball-shaped base 1 (FIG. 1). The base 1 has rigidly attached thereto a pair of guiding columns 2.

Each one of the guiding columns 2 receives therein a reciprocable rod 3. The rod 3 reciprocates within the respective guiding column 2, with the rollers 4 and 5 carried by the rod rolling along the internal surface of the column 2. A pair of rollers 4 is mounted on each one of the shafts 6 (FIG. 2 and 3). The last-mentioned shafts are rigidly secured in the rod 3 and lie in an imaginary diagonal plane passing through the rod 3, at

the opposite sides 7 of the rod 3. The other pair of the opposite sides 8 of the rod 3 has mounted thereon shafts 9 pivotally supporting a pair of arms 10.

The respective internal ends of the arms 10 are interconnected by an extension spring 11, whereas the external ends of the arms 10 support each a roller 5 rotatable about an axis 15.

The upper extremities of the rods 3 have rigidly attached thereto the lateral tubular members 13 (FIGS. 4 and 5). These tubular members are connected to each otherby means of slidable sleeves 14. The provision of the sleeves 14 makes it possible for the rods 3 to be rotated within a limited extent relative to each other in two different planes. The external, i.e. the free ends of the lateral tubular members 13 are associated with respective conical couplings 15. Each of the two conical couplings 15 includes a pair of coupling members 16 and 17. Each external coupling member 16 has mounted thereon brackets 18 supporting a drawing board 19.

In order to facilitate the connecting operations and to provide for the interchangeability of the lateral tubular members 13, each one of these members has a cylindrical counterbore 20 made therein at both ends thereof. This counterbore 20 is adapted to receive either the slidable sleeve 14 with a washer 21, or a coupling member 17. The coupling member 17 is an externally cylindrical insert with a conical bore adapted to receive thereinside the other conical coupling member 16. The coupling members 17 are preferably made of an elastic plastic material, e. g. of capron. The coupling members being made of a plastic material, their manufacture is simplified and the performance of the friction coupling members of each one of the couplings 15 is facilitated.

The coupling members 16 are interconnected by a resilient connecting member 22 passing through all the lateral tubular members 13 carried by the respective rods 3 and thus holding these tubular members 13 together by an effort directed along the axis of these tubular members. Each coupling member 16 is connected with the respective end of the connecting member 22 by the respective threaded connection 24.

Mounted adjacent to the bottom of the base 1 are drum assemblies 25 (FIGS. 6 and 7) for counterbalancing the respective rods 3.

Each drum assembly 25 includes a sleeve 26 receiving thereinside holders 27 with torsion springs 28. Extending centrally of the sleeve 26 is a shaft 29 having its opposite ends journalled in antifriction bearings 30. Each torsion spring 28 has one end thereof connected with the shaft 29 by means of a slot 31 extending along the entire length of the shaft 29 and receiving thereinside the said bent end portion of the spring 28. The opposite end of each torsion spring 28 is connected with the respective holder 27 by means of flaps 32 bent upon the respective holder. The holders 27 have made therein aligned slots 33 adapted to receive the respective ones of spokes 34 rigidly mounted internally of the sleeve 26.

Each shaft 29 has its journal 35 at one end thereof mounted in the respective bracket 36 secured to the base 1, whereas the opposite end of the shaft 29 is mounted in the respective one of arms 37.

The arms 37 are supported by a common axle 38 and are connected by means connecting rods 39 with a control foot pedal 40.

Each drum assembly 25 has wound thereabout a cable 41 of which one end is secured to the sleeve 26, while the other end thereof passes through the guiding column 2, then passes over a sheave 42 (FIG. 2) rotatably mounted on spindles 43 carried by the guiding column 2, and then over a sheave 44 rotatably mounted on a spindle 45 carried by the rod 3, and, finally, this opposite end of the cable is secured to the resilient connecting member 22.

The external surface of each drum assembly 25 has wound thereabout a length of a flat elastic band 46 (FIG. 6) of which the opposite ends are secured to the base 1, the band 46 serving for retaining selectively the respective rod 3 at a desired height. The band 46 is adapted to act as a brake member, i.e. to arrest the rotation of the respective drum 25.

Connected to the resilient connecting member 22, at the respective points of the connection thereto of the cables 41, are extension springs 47 (FIG. 4) associated with the respective adjustment screws, whereby it becomes possible to adjust the wedging effort applied to the conical couplings 15.

In cases when the drawing board 19 is of a relatively great length, the herein disclosed drawing machine can include three reciprocable board-supporting rods 3 mounted each on an individual base 49 (FIG. 8).

In these cases the elastic flat band 46 is wound about only that one of the drums 25 which is positioned downwardly of the central one of the rods 3 whereby it becomes possible to control raising and lowering of the drawing board 19 by means of a single foot pedal 40 positioned to ensure maximal convenience to a draftsman. In these cases firmer mounting of the drawing board 19 can be efiected by means of additional brackets 50 (FIG. 9) carried by the respective slidable sleeves 13 positioned intermediate of the lateral tubular members 13.

The herein disclosed drawing machine is operable, as follows.

The combined weight of the reciprocable rods 3 and of the drawing board 19 acts through the respective cables 41 upon the drums 25 and tries to lift the latter, whereby the elastic bands 46 closely engage the respective drums 25 and arrest their rotation, and, consequently, the rods 3 do not move in their respective columns 2. The force applied to the resilient connecting member 22 is equal to AP P P where:

P is the weight of the movable part of the machine (the drawing board, the rods, etc.);

P is the joint effort of the extended springs 47, which controls the degree of the sagging of the resilient connecting member 22 and the effort wedging the coupling members 16 of the couplings in the coupling mem bers 17, this engagement of the couplings 15 retaining the drawing board in a desired set angular position thereof.

When the board 19 is to be displaced in the vertical plane, the draftsman depresses the foot pedal 40, whereby the arm (the arms) 37 is pivoted, and the drum (drums) 25 is displaced downwardly, the elastic band 46 releasing its grip on the drum (drums) 25, and the latter is rotated about its shaft 29 in a corresponding direction, depending on the direction of the adjustment of the extension of the rods 3. When the drawing board 19 is lowered, the cables 41 are paid off the respective drums 25, and the torsion springs 28 are tensioned.

Alternatively, when the drawing board 19 is being lifted, the cables 41 are taken up by the respective drums 25, the torsion springs 28 are uncoiled, and their bias facilitates the raising of the drawing board 1?.

Adjustment of the angular position of the drawing board 19 relative to the vertical plane is performed independently of the foot pedal 40. When the board 19 is to be rotated into a desired angular position, an upwardly directed effort equal to A P (see above) is to be applied manually to the bottom edge of the drawing board, whereby the resilient connecting member 22 straightens (P P A P), and the wedging effort applied to the couplings 15 and maintaining their engagement is relieved.

As long as this upwardly directed effort is being applied to the bottom edge of the drawing board 19, the latter can be easily set into the desired angular position, whereafter it is sufficient to relieve this effort equal to AP, and the board becomes automatically retained in the set position.

When the rods 3 are being moved in their respective guiding coltunns 2, they are able to align themselves in these columns on account of their lateral tubular members 13 being connected to one another by means of the slidable sleeves 14 and by the holding-together effort of the resilient connecting member 22, and thus the rods 3 run smoothly in their respective columns 2, and their jamming in these columns is prevented. A drawing machine constructed in accordance with the present invention has been used in association with drawing boards of various sizes (particularly, of various lengths), and in all these cases it was assembled from assemblies and parts belonging to the same single basic model.

The test samples of drafting machines, constructed in accordance with the present invention, have demonstrated smooth performance; and, in addition to that, they have proved that such drawing machines can be assembled in various modifications to suit the character of works to be performed.

What we claim is:

1. A drawing machine comprising at least one base structure; a plurality of guiding columns mounted on said base structure; a plurality of rods movably received in the respective ones of said plurality of guiding columns; roller means mounted on each one of said rods for rolling contact with said respective columns, as said rods are moved in said columns; lateral tubular members attached to the end portions of said rods, pro

jecting from the respective ones of said guiding columns, slidable sleeves connecting each adjacent pair of the ends of said lateral tubular members, so that said rods are free for limited rotation relative to one another in at least two planes; a pair of conical couplings mounted on the respective free end of said lateral tubular members; a resilient connecting member interconv necting said pair of couplings and passing throughout said lateral tubular members of all said rods, thus holding said tubular-members together in the direction of the longitudinal axes thereof; bracket means carried by said couplings and adapted to support a drawing board; drum assemblies for counterbalancing said rods, mounted on said base structure beneath each one of said plurality of guiding columns, each said drum assembly including: a shaft extending inside a drum; torsion spring means received inside said drum and having one end thereof connected to said drum and the opposite end thereof connected to said shaft; elongated cable means operatively connecting said resilient connecting member with the respective ones of said drum assemblies; elastic flat band means adapted to retain said rods at a desired height of the extension of said rods from the respective 'ones of said guiding columns, said elastic flat band means being positioned adjacent to the external periphery of said drum and making at least one loop about said periphery of said drum, said elastic flat band means having the opposite ends thereof connected to said base structure; arms mounted on said respective shafts of said drum assemblies at least one control foot pedal mounted on said base structure; a connecting rod establishing operative connection of said foot pedal with said arms.

2. A drawing machine according to claim 1, wherein the opposite end portions of each said lateral tubular member have made therein cylindrical counterbores for receiving thereinside either said slidable sleeves or the coupling members of said conical couplings; each said coupling member receivable within said counterbore being an externally cylindrical part with a conical internal bore.

3. A drawing machine according to claim 2, wherein said externally cylindrical part is made of an elastic plastic material.

4. A drawing machine according to claim 1, wherein said conical couplings are connected with said resilient connecting member by means of threaded connections.

5. A drawing machine according to claim 1, wherein said roller means mounted on each said rod are so arranged that two pairs of said roller means are positioned for each said pair to rotate about a respective axis, said axes being rigidly secured to said rod at a pair of the opposite sides of said rod, at the diagonal points along the length of said rod; said rod further carrying a pair of spring-biased pivotable arms, the respective pivot axes of said arms being mounted on said rod at the other pair of the opposite sides of said rod, at another pair of the diagonal points along the length of said rod; each said arm carrying at least one roller.

6. A drawing machine according to claim 1, including a pair of said movable rods and a pair of said guiding columns, said pair of guiding columns being supported by a single base structure, said arms, included into the operative connection of said shaft of said drum assemblies with said control foot pedal, being mounted for pivoting motion about a common additional axis.

7. A drawing machine according to claim 1, including three said movable rods supported by individual respective base structures, said elastic flat band means adapted to retain said rods at a desired height being associated only with that one of said drum assemblies which is positioned in the central one of said individual base structure.

8. A drawing machine according to claim 1, wherein said slidable sleeves carry additional bracket means adapted to support said drawing board of said machine. 

1. A drawing machine comprising at least one base structure; a plurality of guiding columns mounted on said base structure; a plurality of rods movably received in the respective ones of said plurality of guiding columns; roller means mounted on each one of said rods for rolling contact with said respective columns, as said rods are moved in said columns; lateral tubular members attached to the end portions of said rods, projecting from the respective ones of said guiding columns, slidable sleeves connecting each adjacent pair of the ends of said lateral tubular members, so that said rods are free for limited rotation relative to one another in at least two planes; a pair of conical couplings mounted on the respective free end of said lateral tubular members; a resilient connecting member interconnecting said pair of couplings and passing throughout said lateral tubular members of all said rods, thus holding said tubularmembers together in the direction of the longitudinal axes thereof; bracket means carried by said Couplings and adapted to support a drawing board; drum assemblies for counterbalancing said rods, mounted on said base structure beneath each one of said plurality of guiding columns, each said drum assembly including: a shaft extending inside a drum; torsion spring means received inside said drum and having one end thereof connected to said drum and the opposite end thereof connected to said shaft; elongated cable means operatively connecting said resilient connecting member with the respective ones of said drum assemblies; elastic flat band means adapted to retain said rods at a desired height of the extension of said rods from the respective ones of said guiding columns, said elastic flat band means being positioned adjacent to the external periphery of said drum and making at least one loop about said periphery of said drum, said elastic flat band means having the opposite ends thereof connected to said base structure; arms mounted on said respective shafts of said drum assemblies at least one control foot pedal mounted on said base structure; a connecting rod establishing operative connection of said foot pedal with said arms.
 2. A drawing machine according to claim 1, wherein the opposite end portions of each said lateral tubular member have made therein cylindrical counterbores for receiving thereinside either said slidable sleeves or the coupling members of said conical couplings; each said coupling member receivable within said counterbore being an externally cylindrical part with a conical internal bore.
 3. A drawing machine according to claim 2, wherein said externally cylindrical part is made of an elastic plastic material.
 4. A drawing machine according to claim 1, wherein said conical couplings are connected with said resilient connecting member by means of threaded connections.
 5. A drawing machine according to claim 1, wherein said roller means mounted on each said rod are so arranged that two pairs of said roller means are positioned for each said pair to rotate about a respective axis, said axes being rigidly secured to said rod at a pair of the opposite sides of said rod, at the diagonal points along the length of said rod; said rod further carrying a pair of spring-biased pivotable arms, the respective pivot axes of said arms being mounted on said rod at the other pair of the opposite sides of said rod, at another pair of the diagonal points along the length of said rod; each said arm carrying at least one roller.
 6. A drawing machine according to claim 1, including a pair of said movable rods and a pair of said guiding columns, said pair of guiding columns being supported by a single base structure, said arms, included into the operative connection of said shaft of said drum assemblies with said control foot pedal, being mounted for pivoting motion about a common additional axis.
 7. A drawing machine according to claim 1, including three said movable rods supported by individual respective base structures, said elastic flat band means adapted to retain said rods at a desired height being associated only with that one of said drum assemblies which is positioned in the central one of said individual base structure.
 8. A drawing machine according to claim 1, wherein said slidable sleeves carry additional bracket means adapted to support said drawing board of said machine. 